反应详情

To a solution of the product of step (i) (4.5 g) in absolute ethanol (200 ml) was added 10% palladium-on-charcoal catalyst (1.2 g) and the resulting suspension hydrogenated at ambient temperature and pressure until uptake of hydrogen ceased. The catalyst was removed by filtration through celite and the filtrate was concentrated in vacuo to give ethyl 3-(4-hydroxyphenoxy)butyrate as a low-melting crystalline solid (3.0 g) NMR (d6DMSO): δ1.25 (3H,t); 1.8-2.0 (2H,m); 2.5 (2H,t); 3.9 (2H,t); 4.1 (2H,q); 6.7 (4H,m); 8.8 (1H,br.s); m/e 224 (M)+.

1. customhydrogenated at ambient temperature
2. customThe catalyst was removed by filtration through celite
3. concentrationthe filtrate was concentrated in vacuo